lib/File/Copy.pm

# File/Copy.pm. Written in 1994 by Aaron Sherman <ajs@ajs.com>. This
# source code has been placed in the public domain by the author.
# Please be kind and preserve the documentation.
#
# Additions copyright 1996 by Charles Bailey.  Permission is granted
# to distribute the revised code under the same terms as Perl itself.

package File::Copy;

use 5.006;
use strict;
use warnings;
use Carp;
use File::Spec;
use Config;
our(@ISA, @EXPORT, @EXPORT_OK, $VERSION, $Too_Big, $Syscopy_is_copy);
sub copy;
sub syscopy;
sub cp;
sub mv;

# Note that this module implements only *part* of the API defined by
# the File/Copy.pm module of the File-Tools-2.0 package.  However, that
# package has not yet been updated to work with Perl 5.004, and so it
# would be a Bad Thing for the CPAN module to grab it and replace this
# module.  Therefore, we set this module's version higher than 2.0.
$VERSION = '2.08';

require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(copy move);
@EXPORT_OK = qw(cp mv);

$Too_Big = 1024 * 1024 * 2;

my $macfiles;
if ($^O eq 'MacOS') {
        $macfiles = eval { require Mac::MoreFiles };
        warn 'Mac::MoreFiles could not be loaded; using non-native syscopy'
                if $@ && $^W;
}

sub _catname {
    my($from, $to) = @_;
    if (not defined &basename) {
        require File::Basename;
        import  File::Basename 'basename';
    }

    if ($^O eq 'MacOS') {
        # a partial dir name that's valid only in the cwd (e.g. 'tmp')
        $to = ':' . $to if $to !~ /:/;
    }

    return File::Spec->catfile($to, basename($from));
}

sub copy {
    croak("Usage: copy(FROM, TO [, BUFFERSIZE]) ")
      unless(@_ == 2 || @_ == 3);

    my $from = shift;
    my $to = shift;

    my $from_a_handle = (ref($from)
                         ? (ref($from) eq 'GLOB'
                            || UNIVERSAL::isa($from, 'GLOB')
                            || UNIVERSAL::isa($from, 'IO::Handle'))
                         : (ref(\$from) eq 'GLOB'));
    my $to_a_handle =   (ref($to)
                         ? (ref($to) eq 'GLOB'
                            || UNIVERSAL::isa($to, 'GLOB')
                            || UNIVERSAL::isa($to, 'IO::Handle'))
                         : (ref(\$to) eq 'GLOB'));

    if ($from eq $to) { # works for references, too
        croak("'$from' and '$to' are identical (not copied)");
    }

    if ((($Config{d_symlink} && $Config{d_readlink}) || $Config{d_link}) &&
        !($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'vms')) {
        my @fs = stat($from);
        if (@fs) {
            my @ts = stat($to);
            if (@ts && $fs[0] == $ts[0] && $fs[1] == $ts[1]) {
                croak("'$from' and '$to' are identical (not copied)");
            }
        }
    }

    if (!$from_a_handle && !$to_a_handle && -d $to && ! -d $from) {
        $to = _catname($from, $to);
    }

    if (defined &syscopy && !$Syscopy_is_copy
        && !$to_a_handle
        && !($from_a_handle && $^O eq 'os2' )   # OS/2 cannot handle handles
        && !($from_a_handle && $^O eq 'mpeix')  # and neither can MPE/iX.
        && !($from_a_handle && $^O eq 'MSWin32')
        && !($from_a_handle && $^O eq 'MacOS')
        && !($from_a_handle && $^O eq 'NetWare')
       )
    {
        return syscopy($from, $to);
    }

    my $closefrom = 0;
    my $closeto = 0;
    my ($size, $status, $r, $buf);
    local($\) = '';

    my $from_h;
    if ($from_a_handle) {
       $from_h = $from;
    } else {
        $from = _protect($from) if $from =~ /^\s/s;
       $from_h = \do { local *FH };
       open($from_h, "< $from\0") or goto fail_open1;
       binmode $from_h or die "($!,$^E)";
        $closefrom = 1;
    }

    my $to_h;
    if ($to_a_handle) {
       $to_h = $to;
    } else {
        $to = _protect($to) if $to =~ /^\s/s;
       $to_h = \do { local *FH };
       open($to_h,"> $to\0") or goto fail_open2;
       binmode $to_h or die "($!,$^E)";
        $closeto = 1;
    }

    if (@_) {
        $size = shift(@_) + 0;
        croak("Bad buffer size for copy: $size\n") unless ($size > 0);
    } else {
        $size = tied(*$from_h) ? 0 : -s $from_h || 0;
        $size = 1024 if ($size < 512);
        $size = $Too_Big if ($size > $Too_Big);
    }

    $! = 0;
    for (;;) {
        my ($r, $w, $t);
       defined($r = sysread($from_h, $buf, $size))
            or goto fail_inner;
        last unless $r;
        for ($w = 0; $w < $r; $w += $t) {
           $t = syswrite($to_h, $buf, $r - $w, $w)
                or goto fail_inner;
        }
    }

    close($to_h) || goto fail_open2 if $closeto;
    close($from_h) || goto fail_open1 if $closefrom;

    # Use this idiom to avoid uninitialized value warning.
    return 1;

    # All of these contortions try to preserve error messages...
  fail_inner:
    if ($closeto) {
        $status = $!;
        $! = 0;
       close $to_h;
        $! = $status unless $!;
    }
  fail_open2:
    if ($closefrom) {
        $status = $!;
        $! = 0;
       close $from_h;
        $! = $status unless $!;
    }
  fail_open1:
    return 0;
}

sub move {
    my($from,$to) = @_;
    my($fromsz,$tosz1,$tomt1,$tosz2,$tomt2,$sts,$ossts);

    if (-d $to && ! -d $from) {
        $to = _catname($from, $to);
    }

    ($tosz1,$tomt1) = (stat($to))[7,9];
    $fromsz = -s $from;
    if ($^O eq 'os2' and defined $tosz1 and defined $fromsz) {
      # will not rename with overwrite
      unlink $to;
    }
    return 1 if rename $from, $to;

    # Did rename return an error even though it succeeded, because $to
    # is on a remote NFS file system, and NFS lost the server's ack?
    return 1 if defined($fromsz) && !-e $from &&           # $from disappeared
                (($tosz2,$tomt2) = (stat($to))[7,9]) &&    # $to's there
                ($tosz1 != $tosz2 or $tomt1 != $tomt2) &&  #   and changed
                $tosz2 == $fromsz;                         # it's all there

    ($tosz1,$tomt1) = (stat($to))[7,9];  # just in case rename did something
    return 1 if copy($from,$to) && unlink($from);
    ($sts,$ossts) = ($! + 0, $^E + 0);

    ($tosz2,$tomt2) = ((stat($to))[7,9],0,0) if defined $tomt1;
    unlink($to) if !defined($tomt1) or $tomt1 != $tomt2 or $tosz1 != $tosz2;
    ($!,$^E) = ($sts,$ossts);
    return 0;
}

*cp = \&copy;
*mv = \&move;


if ($^O eq 'MacOS') {
    *_protect = sub { MacPerl::MakeFSSpec($_[0]) };
} else {
    *_protect = sub { "./$_[0]" };
}

# &syscopy is an XSUB under OS/2
unless (defined &syscopy) {
    if ($^O eq 'VMS') {
        *syscopy = \&rmscopy;
    } elsif ($^O eq 'mpeix') {
        *syscopy = sub {
            return 0 unless @_ == 2;
            # Use the MPE cp program in order to
            # preserve MPE file attributes.
            return system('/bin/cp', '-f', $_[0], $_[1]) == 0;
        };
    } elsif ($^O eq 'MSWin32') {
        *syscopy = sub {
            return 0 unless @_ == 2;
            return Win32::CopyFile(@_, 1);
        };
    } elsif ($macfiles) {
        *syscopy = sub {
            my($from, $to) = @_;
            my($dir, $toname);

            return 0 unless -e $from;

            if ($to =~ /(.*:)([^:]+):?$/) {
                ($dir, $toname) = ($1, $2);
            } else {
                ($dir, $toname) = (":", $to);
            }

            unlink($to);
            Mac::MoreFiles::FSpFileCopy($from, $dir, $toname, 1);
        };
    } else {
        $Syscopy_is_copy = 1;
        *syscopy = \&copy;
    }
}

1;

__END__

=head1 NAME

File::Copy - Copy files or filehandles

=head1 SYNOPSIS

        use File::Copy;

        copy("file1","file2") or die "Copy failed: $!";
        copy("Copy.pm",\*STDOUT);
        move("/dev1/fileA","/dev2/fileB");

        use File::Copy "cp";

        $n = FileHandle->new("/a/file","r");
        cp($n,"x");

=head1 DESCRIPTION

The File::Copy module provides two basic functions, C<copy> and
C<move>, which are useful for getting the contents of a file from
one place to another.

=over 4

=item *

The C<copy> function takes two
parameters: a file to copy from and a file to copy to. Either
argument may be a string, a FileHandle reference or a FileHandle
glob. Obviously, if the first argument is a filehandle of some
sort, it will be read from, and if it is a file I<name> it will
be opened for reading. Likewise, the second argument will be
written to (and created if need be).  Trying to copy a file on top
of itself is a fatal error.

B<Note that passing in
files as handles instead of names may lead to loss of information
on some operating systems; it is recommended that you use file
names whenever possible.>  Files are opened in binary mode where
applicable.  To get a consistent behaviour when copying from a
filehandle to a file, use C<binmode> on the filehandle.

An optional third parameter can be used to specify the buffer
size used for copying. This is the number of bytes from the
first file, that wil be held in memory at any given time, before
being written to the second file. The default buffer size depends
upon the file, but will generally be the whole file (up to 2Mb), or
1k for filehandles that do not reference files (eg. sockets).

You may use the syntax C<use File::Copy "cp"> to get at the
"cp" alias for this function. The syntax is I<exactly> the same.

=item *

The C<move> function also takes two parameters: the current name
and the intended name of the file to be moved.  If the destination
already exists and is a directory, and the source is not a
directory, then the source file will be renamed into the directory
specified by the destination.

If possible, move() will simply rename the file.  Otherwise, it copies
the file to the new location and deletes the original.  If an error occurs
during this copy-and-delete process, you may be left with a (possibly partial)
copy of the file under the destination name.

You may use the "mv" alias for this function in the same way that
you may use the "cp" alias for C<copy>.

=back

File::Copy also provides the C<syscopy> routine, which copies the
file specified in the first parameter to the file specified in the
second parameter, preserving OS-specific attributes and file
structure.  For Unix systems, this is equivalent to the simple
C<copy> routine, which doesn't preserve OS-specific attributes.  For
VMS systems, this calls the C<rmscopy> routine (see below).  For OS/2
systems, this calls the C<syscopy> XSUB directly. For Win32 systems,
this calls C<Win32::CopyFile>.

On Mac OS (Classic), C<syscopy> calls C<Mac::MoreFiles::FSpFileCopy>,
if available.

=head2 Special behaviour if C<syscopy> is defined (OS/2, VMS and Win32)

If both arguments to C<copy> are not file handles,
then C<copy> will perform a "system copy" of
the input file to a new output file, in order to preserve file
attributes, indexed file structure, I<etc.>  The buffer size
parameter is ignored.  If either argument to C<copy> is a
handle to an opened file, then data is copied using Perl
operators, and no effort is made to preserve file attributes
or record structure.

The system copy routine may also be called directly under VMS and OS/2
as C<File::Copy::syscopy> (or under VMS as C<File::Copy::rmscopy>, which
is the routine that does the actual work for syscopy).

=over 4

=item rmscopy($from,$to[,$date_flag])

The first and second arguments may be strings, typeglobs, typeglob
references, or objects inheriting from IO::Handle;
they are used in all cases to obtain the
I<filespec> of the input and output files, respectively.  The
name and type of the input file are used as defaults for the
output file, if necessary.

A new version of the output file is always created, which
inherits the structure and RMS attributes of the input file,
except for owner and protections (and possibly timestamps;
see below).  All data from the input file is copied to the
output file; if either of the first two parameters to C<rmscopy>
is a file handle, its position is unchanged.  (Note that this
means a file handle pointing to the output file will be
associated with an old version of that file after C<rmscopy>
returns, not the newly created version.)

The third parameter is an integer flag, which tells C<rmscopy>
how to handle timestamps.  If it is E<lt> 0, none of the input file's
timestamps are propagated to the output file.  If it is E<gt> 0, then
it is interpreted as a bitmask: if bit 0 (the LSB) is set, then
timestamps other than the revision date are propagated; if bit 1
is set, the revision date is propagated.  If the third parameter
to C<rmscopy> is 0, then it behaves much like the DCL COPY command:
if the name or type of the output file was explicitly specified,
then no timestamps are propagated, but if they were taken implicitly
from the input filespec, then all timestamps other than the
revision date are propagated.  If this parameter is not supplied,
it defaults to 0.

Like C<copy>, C<rmscopy> returns 1 on success.  If an error occurs,
it sets C<$!>, deletes the output file, and returns 0.

=back

=head1 RETURN

All functions return 1 on success, 0 on failure.
$! will be set if an error was encountered.

=head1 NOTES

=over 4

=item *

On Mac OS (Classic), the path separator is ':', not '/', and the 
current directory is denoted as ':', not '.'. You should be careful 
about specifying relative pathnames. While a full path always begins 
with a volume name, a relative pathname should always begin with a 
':'.  If specifying a volume name only, a trailing ':' is required.

E.g.

  copy("file1", "tmp");        # creates the file 'tmp' in the current directory
  copy("file1", ":tmp:");      # creates :tmp:file1
  copy("file1", ":tmp");       # same as above
  copy("file1", "tmp");        # same as above, if 'tmp' is a directory (but don't do   
                               # that, since it may cause confusion, see example #1)
  copy("file1", "tmp:file1");  # error, since 'tmp:' is not a volume
  copy("file1", ":tmp:file1"); # ok, partial path
  copy("file1", "DataHD:");    # creates DataHD:file1
  
  move("MacintoshHD:fileA", "DataHD:fileB"); # moves (don't copies) files from one 
                                             # volume to another

=back

=head1 AUTHOR

File::Copy was written by Aaron Sherman I<E<lt>ajs@ajs.comE<gt>> in 1995,
and updated by Charles Bailey I<E<lt>bailey@newman.upenn.eduE<gt>> in 1996.

=cut

Revision:	1.1
Committed:	Thu Jun 30 14:27:11 2005 UTC (21 years, 3 months ago) by root
Branch:	MAIN
CVS Tags:	PERL-5-8-7, HEAD
Branch point for:	PERL
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	# File/Copy.pm. Written in 1994 by Aaron Sherman <ajs@ajs.com>. This
2			# source code has been placed in the public domain by the author.
3			# Please be kind and preserve the documentation.
4			#
5			# Additions copyright 1996 by Charles Bailey. Permission is granted
6			# to distribute the revised code under the same terms as Perl itself.
7
8			package File::Copy;
9
10			use 5.006;
11			use strict;
12			use warnings;
13			use Carp;
14			use File::Spec;
15			use Config;
16			our(@ISA, @EXPORT, @EXPORT_OK, $VERSION, $Too_Big, $Syscopy_is_copy);
17			sub copy;
18			sub syscopy;
19			sub cp;
20			sub mv;
21
22			# Note that this module implements only part of the API defined by
23			# the File/Copy.pm module of the File-Tools-2.0 package. However, that
24			# package has not yet been updated to work with Perl 5.004, and so it
25			# would be a Bad Thing for the CPAN module to grab it and replace this
26			# module. Therefore, we set this module's version higher than 2.0.
27			$VERSION = '2.08';
28
29			require Exporter;
30			@ISA = qw(Exporter);
31			@EXPORT = qw(copy move);
32			@EXPORT_OK = qw(cp mv);
33
34			$Too_Big = 1024 * 1024 * 2;
35
36			my $macfiles;
37			if ($^O eq 'MacOS') {
38			$macfiles = eval { require Mac::MoreFiles };
39			warn 'Mac::MoreFiles could not be loaded; using non-native syscopy'
40			if $@ && $^W;
41			}
42
43			sub _catname {
44			my($from, $to) = @_;
45			if (not defined &basename) {
46			require File::Basename;
47			import File::Basename 'basename';
48			}
49
50			if ($^O eq 'MacOS') {
51			# a partial dir name that's valid only in the cwd (e.g. 'tmp')
52			$to = ':' . $to if $to !~ /:/;
53			}
54
55			return File::Spec->catfile($to, basename($from));
56			}
57
58			sub copy {
59			croak("Usage: copy(FROM, TO [, BUFFERSIZE]) ")
60			unless(@_ == 2 \|\| @_ == 3);
61
62			my $from = shift;
63			my $to = shift;
64
65			my $from_a_handle = (ref($from)
66			? (ref($from) eq 'GLOB'
67			\|\| UNIVERSAL::isa($from, 'GLOB')
68			\|\| UNIVERSAL::isa($from, 'IO::Handle'))
69			: (ref(\$from) eq 'GLOB'));
70			my $to_a_handle = (ref($to)
71			? (ref($to) eq 'GLOB'
72			\|\| UNIVERSAL::isa($to, 'GLOB')
73			\|\| UNIVERSAL::isa($to, 'IO::Handle'))
74			: (ref(\$to) eq 'GLOB'));
75
76			if ($from eq $to) { # works for references, too
77			croak("'$from' and '$to' are identical (not copied)");
78			}
79
80			if ((($Config{d_symlink} && $Config{d_readlink}) \|\| $Config{d_link}) &&
81			!($^O eq 'MSWin32' \|\| $^O eq 'os2' \|\| $^O eq 'vms')) {
82			my @fs = stat($from);
83			if (@fs) {
84			my @ts = stat($to);
85			if (@ts && $fs[0] == $ts[0] && $fs[1] == $ts[1]) {
86			croak("'$from' and '$to' are identical (not copied)");
87			}
88			}
89			}
90
91			if (!$from_a_handle && !$to_a_handle && -d $to && ! -d $from) {
92			$to = _catname($from, $to);
93			}
94
95			if (defined &syscopy && !$Syscopy_is_copy
96			&& !$to_a_handle
97			&& !($from_a_handle && $^O eq 'os2' ) # OS/2 cannot handle handles
98			&& !($from_a_handle && $^O eq 'mpeix') # and neither can MPE/iX.
99			&& !($from_a_handle && $^O eq 'MSWin32')
100			&& !($from_a_handle && $^O eq 'MacOS')
101			&& !($from_a_handle && $^O eq 'NetWare')
102			)
103			{
104			return syscopy($from, $to);
105			}
106
107			my $closefrom = 0;
108			my $closeto = 0;
109			my ($size, $status, $r, $buf);
110			local($\) = '';
111
112			my $from_h;
113			if ($from_a_handle) {
114			$from_h = $from;
115			} else {
116			$from = _protect($from) if $from =~ /^\s/s;
117			$from_h = \do { local *FH };
118			open($from_h, "< $from\0") or goto fail_open1;
119			binmode $from_h or die "($!,$^E)";
120			$closefrom = 1;
121			}
122
123			my $to_h;
124			if ($to_a_handle) {
125			$to_h = $to;
126			} else {
127			$to = _protect($to) if $to =~ /^\s/s;
128			$to_h = \do { local *FH };
129			open($to_h,"> $to\0") or goto fail_open2;
130			binmode $to_h or die "($!,$^E)";
131			$closeto = 1;
132			}
133
134			if (@_) {
135			$size = shift(@_) + 0;
136			croak("Bad buffer size for copy: $size\n") unless ($size > 0);
137			} else {
138			$size = tied(*$from_h) ? 0 : -s $from_h \|\| 0;
139			$size = 1024 if ($size < 512);
140			$size = $Too_Big if ($size > $Too_Big);
141			}
142
143			$! = 0;
144			for (;;) {
145			my ($r, $w, $t);
146			defined($r = sysread($from_h, $buf, $size))
147			or goto fail_inner;
148			last unless $r;
149			for ($w = 0; $w < $r; $w += $t) {
150			$t = syswrite($to_h, $buf, $r - $w, $w)
151			or goto fail_inner;
152			}
153			}
154
155			close($to_h) \|\| goto fail_open2 if $closeto;
156			close($from_h) \|\| goto fail_open1 if $closefrom;
157
158			# Use this idiom to avoid uninitialized value warning.
159			return 1;
160
161			# All of these contortions try to preserve error messages...
162			fail_inner:
163			if ($closeto) {
164			$status = $!;
165			$! = 0;
166			close $to_h;
167			$! = $status unless $!;
168			}
169			fail_open2:
170			if ($closefrom) {
171			$status = $!;
172			$! = 0;
173			close $from_h;
174			$! = $status unless $!;
175			}
176			fail_open1:
177			return 0;
178			}
179
180			sub move {
181			my($from,$to) = @_;
182			my($fromsz,$tosz1,$tomt1,$tosz2,$tomt2,$sts,$ossts);
183
184			if (-d $to && ! -d $from) {
185			$to = _catname($from, $to);
186			}
187
188			($tosz1,$tomt1) = (stat($to))[7,9];
189			$fromsz = -s $from;
190			if ($^O eq 'os2' and defined $tosz1 and defined $fromsz) {
191			# will not rename with overwrite
192			unlink $to;
193			}
194			return 1 if rename $from, $to;
195
196			# Did rename return an error even though it succeeded, because $to
197			# is on a remote NFS file system, and NFS lost the server's ack?
198			return 1 if defined($fromsz) && !-e $from && # $from disappeared
199			(($tosz2,$tomt2) = (stat($to))[7,9]) && # $to's there
200			($tosz1 != $tosz2 or $tomt1 != $tomt2) && # and changed
201			$tosz2 == $fromsz; # it's all there
202
203			($tosz1,$tomt1) = (stat($to))[7,9]; # just in case rename did something
204			return 1 if copy($from,$to) && unlink($from);
205			($sts,$ossts) = ($! + 0, $^E + 0);
206
207			($tosz2,$tomt2) = ((stat($to))[7,9],0,0) if defined $tomt1;
208			unlink($to) if !defined($tomt1) or $tomt1 != $tomt2 or $tosz1 != $tosz2;
209			($!,$^E) = ($sts,$ossts);
210			return 0;
211			}
212
213			*cp = \©
214			*mv = \&move;
215
216
217			if ($^O eq 'MacOS') {
218			*_protect = sub { MacPerl::MakeFSSpec($_[0]) };
219			} else {
220			*_protect = sub { "./$_[0]" };
221			}
222
223			# &syscopy is an XSUB under OS/2
224			unless (defined &syscopy) {
225			if ($^O eq 'VMS') {
226			*syscopy = \&rmscopy;
227			} elsif ($^O eq 'mpeix') {
228			*syscopy = sub {
229			return 0 unless @_ == 2;
230			# Use the MPE cp program in order to
231			# preserve MPE file attributes.
232			return system('/bin/cp', '-f', $_[0], $_[1]) == 0;
233			};
234			} elsif ($^O eq 'MSWin32') {
235			*syscopy = sub {
236			return 0 unless @_ == 2;
237			return Win32::CopyFile(@_, 1);
238			};
239			} elsif ($macfiles) {
240			*syscopy = sub {
241			my($from, $to) = @_;
242			my($dir, $toname);
243
244			return 0 unless -e $from;
245
246			if ($to =~ /(.*:)([^:]+):?$/) {
247			($dir, $toname) = ($1, $2);
248			} else {
249			($dir, $toname) = (":", $to);
250			}
251
252			unlink($to);
253			Mac::MoreFiles::FSpFileCopy($from, $dir, $toname, 1);
254			};
255			} else {
256			$Syscopy_is_copy = 1;
257			*syscopy = \©
258			}
259			}
260
261			1;
262
263			__END__
264
265			=head1 NAME
266
267			File::Copy - Copy files or filehandles
268
269			=head1 SYNOPSIS
270
271			use File::Copy;
272
273			copy("file1","file2") or die "Copy failed: $!";
274			copy("Copy.pm",\*STDOUT);
275			move("/dev1/fileA","/dev2/fileB");
276
277			use File::Copy "cp";
278
279			$n = FileHandle->new("/a/file","r");
280			cp($n,"x");
281
282			=head1 DESCRIPTION
283
284			The File::Copy module provides two basic functions, C<copy> and
285			C<move>, which are useful for getting the contents of a file from
286			one place to another.
287
288			=over 4
289
290			=item *
291
292			The C<copy> function takes two
293			parameters: a file to copy from and a file to copy to. Either
294			argument may be a string, a FileHandle reference or a FileHandle
295			glob. Obviously, if the first argument is a filehandle of some
296			sort, it will be read from, and if it is a file I<name> it will
297			be opened for reading. Likewise, the second argument will be
298			written to (and created if need be). Trying to copy a file on top
299			of itself is a fatal error.
300
301			B<Note that passing in
302			files as handles instead of names may lead to loss of information
303			on some operating systems; it is recommended that you use file
304			names whenever possible.> Files are opened in binary mode where
305			applicable. To get a consistent behaviour when copying from a
306			filehandle to a file, use C<binmode> on the filehandle.
307
308			An optional third parameter can be used to specify the buffer
309			size used for copying. This is the number of bytes from the
310			first file, that wil be held in memory at any given time, before
311			being written to the second file. The default buffer size depends
312			upon the file, but will generally be the whole file (up to 2Mb), or
313			1k for filehandles that do not reference files (eg. sockets).
314
315			You may use the syntax C<use File::Copy "cp"> to get at the
316			"cp" alias for this function. The syntax is I<exactly> the same.
317
318			=item *
319
320			The C<move> function also takes two parameters: the current name
321			and the intended name of the file to be moved. If the destination
322			already exists and is a directory, and the source is not a
323			directory, then the source file will be renamed into the directory
324			specified by the destination.
325
326			If possible, move() will simply rename the file. Otherwise, it copies
327			the file to the new location and deletes the original. If an error occurs
328			during this copy-and-delete process, you may be left with a (possibly partial)
329			copy of the file under the destination name.
330
331			You may use the "mv" alias for this function in the same way that
332			you may use the "cp" alias for C<copy>.
333
334			=back
335
336			File::Copy also provides the C<syscopy> routine, which copies the
337			file specified in the first parameter to the file specified in the
338			second parameter, preserving OS-specific attributes and file
339			structure. For Unix systems, this is equivalent to the simple
340			C<copy> routine, which doesn't preserve OS-specific attributes. For
341			VMS systems, this calls the C<rmscopy> routine (see below). For OS/2
342			systems, this calls the C<syscopy> XSUB directly. For Win32 systems,
343			this calls C<Win32::CopyFile>.
344
345			On Mac OS (Classic), C<syscopy> calls C<Mac::MoreFiles::FSpFileCopy>,
346			if available.
347
348			=head2 Special behaviour if C<syscopy> is defined (OS/2, VMS and Win32)
349
350			If both arguments to C<copy> are not file handles,
351			then C<copy> will perform a "system copy" of
352			the input file to a new output file, in order to preserve file
353			attributes, indexed file structure, I<etc.> The buffer size
354			parameter is ignored. If either argument to C<copy> is a
355			handle to an opened file, then data is copied using Perl
356			operators, and no effort is made to preserve file attributes
357			or record structure.
358
359			The system copy routine may also be called directly under VMS and OS/2
360			as C<File::Copy::syscopy> (or under VMS as C<File::Copy::rmscopy>, which
361			is the routine that does the actual work for syscopy).
362
363			=over 4
364
365			=item rmscopy($from,$to[,$date_flag])
366
367			The first and second arguments may be strings, typeglobs, typeglob
368			references, or objects inheriting from IO::Handle;
369			they are used in all cases to obtain the
370			I<filespec> of the input and output files, respectively. The
371			name and type of the input file are used as defaults for the
372			output file, if necessary.
373
374			A new version of the output file is always created, which
375			inherits the structure and RMS attributes of the input file,
376			except for owner and protections (and possibly timestamps;
377			see below). All data from the input file is copied to the
378			output file; if either of the first two parameters to C<rmscopy>
379			is a file handle, its position is unchanged. (Note that this
380			means a file handle pointing to the output file will be
381			associated with an old version of that file after C<rmscopy>
382			returns, not the newly created version.)
383
384			The third parameter is an integer flag, which tells C<rmscopy>
385			how to handle timestamps. If it is E<lt> 0, none of the input file's
386			timestamps are propagated to the output file. If it is E<gt> 0, then
387			it is interpreted as a bitmask: if bit 0 (the LSB) is set, then
388			timestamps other than the revision date are propagated; if bit 1
389			is set, the revision date is propagated. If the third parameter
390			to C<rmscopy> is 0, then it behaves much like the DCL COPY command:
391			if the name or type of the output file was explicitly specified,
392			then no timestamps are propagated, but if they were taken implicitly
393			from the input filespec, then all timestamps other than the
394			revision date are propagated. If this parameter is not supplied,
395			it defaults to 0.
396
397			Like C<copy>, C<rmscopy> returns 1 on success. If an error occurs,
398			it sets C<$!>, deletes the output file, and returns 0.
399
400			=back
401
402			=head1 RETURN
403
404			All functions return 1 on success, 0 on failure.
405			$! will be set if an error was encountered.
406
407			=head1 NOTES
408
409			=over 4
410
411			=item *
412
413			On Mac OS (Classic), the path separator is ':', not '/', and the
414			current directory is denoted as ':', not '.'. You should be careful
415			about specifying relative pathnames. While a full path always begins
416			with a volume name, a relative pathname should always begin with a
417			':'. If specifying a volume name only, a trailing ':' is required.
418
419			E.g.
420
421			copy("file1", "tmp"); # creates the file 'tmp' in the current directory
422			copy("file1", ":tmp:"); # creates :tmp:file1
423			copy("file1", ":tmp"); # same as above
424			copy("file1", "tmp"); # same as above, if 'tmp' is a directory (but don't do
425			# that, since it may cause confusion, see example #1)
426			copy("file1", "tmp:file1"); # error, since 'tmp:' is not a volume
427			copy("file1", ":tmp:file1"); # ok, partial path
428			copy("file1", "DataHD:"); # creates DataHD:file1
429
430			move("MacintoshHD:fileA", "DataHD:fileB"); # moves (don't copies) files from one
431			# volume to another
432
433			=back
434
435			=head1 AUTHOR
436
437			File::Copy was written by Aaron Sherman I<E<lt>ajs@ajs.comE<gt>> in 1995,
438			and updated by Charles Bailey I<E<lt>bailey@newman.upenn.eduE<gt>> in 1996.
439
440			=cut
441